All it takes is one bad day to reduce the sanest man alive to lunacy. That's how far the world is from where I am. Just one bad day. You had a bad day once. Am I right? I know I am. I can tell. You had a bad day and everything changed. Why else would you dress up like a flying rat?
~ The Joker's famous monologue to Batman in The Killing Joke.
All of the enemies of the Dark Knight, Batman. Whether they are from the comics, films, television series, or video games, Batman has a large rouges gallery. Some of them are enemies of Robin, Batgirl, Catwoman, Birds of Prey, the Outsiders, and Police Commissioner James Gordon. Villains from the animated series Batman Beyond are included on this list, as well as the live action TV show Gotham. Also, villains from the Batman: Arkham video-game franchise are included here.